African American students were 3.2 times as likely as white students to be expelled, according to data from the 2012-13 school year. (Portland Public Schools had the highest rate, followed by the Parkrose and Reynolds school districts.)

The top three reasons those interviewed gave for why they joined gangs: a relative or friend was in a gang, to make money as they were surrounded by poverty or family problems, according to the county survey.

View full sizeAntoinette Edwards, director of Portland's Office of Youth Violence Prevention said of the county study, "This is serious. This is timely. Two homicides in one week is unacceptable, and I'm concerned.''Maxine Bernstein/The Oregonian

One-quarter of the gang members surveyed in the one-on-one sessions were in prison at the time.

Multnomah County community health workers and staff from the Oregon Youth Authority and the Multnomah County Sheriff's Office conducted the interviews.

They were part of a larger Multnomah County gang assessment done this year to help define the problem of gang and youth violence, identify gaps in services for gang-affected youths and families and seek potential federal or state money to help support additional programs.

The first phase of the assessment was presented Tuesday to the executive committee of the county's Local Public Safety Coordinating Council. The council met at Gresham City Hall.

"This is serious. This is timely,'' said Antoinette Edwards, director of Portland's Office of Youth Violence Prevention. "Two homicides in one week is unacceptable, and I'm concerned.''

Edwards referred to unsolved gang-related killings in Portland since the end of June. At least 10 bullets were fired in a drive-by shooting on North Fessenden Street in the mid-afternoon on June 30, killing 24-year-old Andrew Coggins Jr. Early Saturday, 26-year-old Hahrahcio Branch was fatally shot outside a Southeast Portland strip club.

View full sizeAn 8-month snapshot of reported gang-related violence in Multnomah County, from Oct. 1, 2013 through May 31, 2014.Source: Multnomah County

The study confirmed what law enforcement agencies have noticed over the past couple of years: Gang violence is no longer concentrated in North or Northeast Portland, but has spread to east county. Particularly, the violence has spread to neighborhoods with the lowest median household income, lowest level of education and the highest density of children.

"There's lots of our communities that are being touched in some way by gang violence,'' said Kim Bernard, a research manager with Multnomah County's Department of Justice who helped present the study at the meeting.

While "shots fired'' calls countywide decreased 16 percent from 2003-04 to 2012-13, the calls spread across the county, with concentrations in the last year found in Gresham's Rockwood neighborhood, the Humboldt and King neighborhoods of Northeast Portland and Portland's downtown/Old Town and Chinatown neighborhoods.

Countywide, reported aggravated assaults that did not involve domestic violence dropped by 24 percent from 2003-04 to 2012-13, but such reports increased more than 8 percent during that time in the Rockwood neighborhood, the study found.

In conducting the study, county officials quickly learned that there's no consistent way among law enforcement agencies for tracking gang violence or identifying gang members or gang associates.

"We're not all measuring, collecting or reporting the same way,'' said Lore Joplin, a consultant hired by the public safety council to help compile the report.

View full sizeChristina McMahan, assistant director of Multnomah County's Department of Community Justice, called the school expulsion data disturbing. "It's pretty mind-blowing,'' she said. The data showed that 18.13 percent of African American students were expelled from a school in Multnomah County during the 2012-13 school year, compared to 5.68 percent of white students.Source: Multnomah County

The Multnomah County District Attorney's gang prosecution unit issued 41 percent fewer felony cases from 2012 to 2013, but double the number of gang-related misdemeanor cases in that period. This was likely due to an increase in federal grant money that boosted the office's misdemeanor unit, officials said.

And, while the study identified 469 programs in the county designed to serve youths and their families, only 22 programs, or 5 percent, were specifically geared toward helping gang members.

The county found that the top reasons people leave gangs is because they've become a parent, have other family responsibilities, are getting married or face pressure from a family member.

Multnomah County presiding Judge Nan Waller said judges need to be more aware of these motivating factors for gang members to leave the gang lifestyle. "We need to take better advantage of that. I don't think judges even ask, 'Are you a parent?'"

A survey of parents of gang-involved youths said they believe available jobs, mentors, recreational programs for youths and greater parental involvement are needed to reduce gang problems.

Rebecca Stavenjord, a project director in the county's health department, said gang-involved youths and young adults emphasized that mentors who had lived the gang life and have learned to get out of it would have the most influence on them.

"There needs to be mentors who get it, who have lived it...to build that trust,'' Stavenjord said.

She urged county leaders to make sure former gang members who can serve as mentors are involved in the next phase of the study, helping to develop ways to address the gaps in county services.